The development of an algorithm to track blood pressure accurately based on the pulse transit time method

Oscillometric blood pressure (BP) monitors are currently used to diagnose hypertension both in home and clinical settings. These monitors take BP measurements once every 15 minutes over a 24 hour period and provide a reliable and accurate system that is minimally invasive. Although intermittent cuff measurements have proven to be a good indicator of BP, a continuous BP monitor is highly desirable for the diagnosis of hypertension and other cardiac diseases. However, no such devices currently exist. A novel algorithm has been developed based on the Pulse Transit Time (PTT) method, which would allow non-invasive and continuous BP measurement. PTT is defined as the time it takes the BP wave to propagate from the heart to a specified point on the body. After an initial BP measurement, PTT algorithms can track BP over short periods of time, known as calibration intervals. After this time has elapsed, a new BP measurement is required to recalibrate the algorithm. Using the PhysioNet database as a basis, the new algorithm was developed and tested using 15 patients, each tested 3 times over a period of 30 minutes. The predicted BP of the algorithm was compared to the arterial BP of each patient. It has been established that this new algorithm is capable of tracking BP over 12 minutes without the need for recalibration, using the BHS standard, a 100% improvement over what has been previously identified. The algorithm was incorporated into a new system based on its requirements and was tested using three volunteers. The results mirrored those previously observed, providing accurate BP measurements when a 12 minute calibration interval was used. This new system provides a significant improvement to the existing method allowing BP to be monitored continuously and non-invasively, on a beat-to-beat basis over 24 hours, adding major clinical and diagnostic value.

Manifestations of heavenly light and fire and the construction of a saint: sanctity, mission and salvation in Adomnán's Vita Columbae

This thesis examines the late seventh-century Latin Life of Columba (Vita Columbae) in a context sympathetic to the spiritual aims and formative intellectual background of its author, Adomnán of Iona. It argues that the Vita Columbae is a sophisticated work, shaped by Adomnán’s spiritual and theological concerns. This sophistication is revealed by a forensic examination of Adomnán’s representation of Columba’s sanctity through a series of miracles, in particular, miracle stories depicting divine manifestations of fire and light. This thesis considers the form and function of these miracle stories in the context of biblical, patristic and medieval interpretations of their archetypes, towards revealing the underlying influence of scriptural, hagiographical and monastic models of sanctity. Chapter one evaluates the function of the Vita Columbae, and outlines the core themes of sanctity which pervade the work, by considering the technical terminology and literary devices found in the opening prefaces in the context of the wider monastic tradition. Chapter two examines Adomnán’s use of biblical models of sanctity to establish Columba’s sanctity, and their relationship between these models and certain miraculous episodes in the Vita Columbae. Chapter three investigates Adomnán’s description of the Holy Spirit as an illuminating fire, and its significance for his portrayal of the saint, by means of a forensic examination of biblical, exegetical and hagiographical treatments of the image. Chapter four examines the missiological, soteriological and providential elements contributing to Adomnán’s portrayal of Columba’s sanctity, as conveyed through the presence of biblical models, particularly the image of the column of fire. Chapter five establishes the influence of monastic examinations of the contemplative life on Adomnán’s portrayal of Columba’s sanctity, and shows how that sanctity is confirmed in terms of his ability to contemplate divine light.